This invention relates generally to an arrangement for open-end friction spinning having two rollers that are arranged next to one another and are drivable in the same rotational direction. The rollers are disposed in a joint structural unit and form a wedge-shaped gap used for the formation of yarn. A mouth of a fiber feeding duct is located opposite the wedge-shaped gap.
In a known arrangement of the initially mentioned type as disclosed in German Application DE-OS No. 33 06 225, the fiber feeding duct leading from an opening roller to the wedge-shaped gap is divided. The part of the fiber feeding duct that is located in the area of the rollers which terminates with a mouth that is opposite the wedge-shaped gap is housed in a pivotable housing part. This housing part can be swivelled away from the rollers for exposing the wedge-shaped gap. As a result, the wedge-shaped gap as well as the interior of the fiber feeding duct become easily accessible for servicing. In practice, it was found that the position of the fiber feeding duct relative to the wedge-shaped gap and in particular the position of the mouth of the fiber feeding duct have an effect on the spinning result. It is therefore necessary that a very precise positioning be made possible in which case the tolerances should not exceed the magnitude of 100 microns. This means that for the pivotal bearing as well as for the locking of the operating position correspondingly narrow tolerances must be maintained which, in the case of a series production, can be realized only with relatively high manufacturing expenditures.
In the case of another construction disclosed in German EP-OS No. 52 412, two exposed rollers are provided. In order to be able to clean the wedge-shaped gap, into which a stationarily arranged fiber feeding duct leads, one of the two rollers can be swivelled away from the fiber feeding duct and the other roller. The cleaning possibilities are limited because the parts are not completely accessible. However, in addition, because of the required precisions, especially for maintaining the distance between the two rollers with respect to one another, very high manufacturing expenditures are necessary.
One object of the present invention is the provision of an arrangement of the initially mentioned type in such a way that the selected positioning distances between the rollers and the mouth of the fiber feeding duct is safely maintained even over an extended operating time.
Another object of the present invention is the provision of such an arrangement without the requirement of high expenditures in view of series production.
These and other objects are attained by providing an arrangement wherein there is a connection between at least one part of the fiber feeding duct containing the mouth and the structural part receiving the shafts of the rollers by means of a rigid connecting device.
By means of this type of stationary arrangement of the fiber feeding duct with respect to the rollers, it is possible to precisely adjust the required distances in the manufacturing plant without the requirement of changes during the operating time. The means that are required for these adjustments may then be used for a plurality of devices so that the costs required for this purpose are not expensive.
In one development of the invention, it is provided that the part of the fiber feeding duct containing the mouth is contained in a structural part which, by means of one or several webs, is mounted at a roller housing receiving the shafts of the rollers and that a structural part containing the other part of the fiber duct is movable with respect to the other structural part. As a result, it is achieved that the overall accessibility of the individual elements is not too restricted.
In the case of another developement, it is provided that the fiber feeding duct is constructed in one part with an opening roller housing which is mounted at a roller housing receiving the shafts of the rollers. This would also result in a simple structural unit.
In another embodiment of the invention, it is provided that an opening roller housing which contains a part of the fiber feeding duct is rigidly fastened at a roller housing receiving the shafts of the roller and that, at the opening roller housing, a structural part is rigidly fastened that has the part of the fiber feeding duct containing the mouth. In the case of this embodiment also, prefabricated structural units may be created that can be adjusted in the manufacturing plant.
In a further development of the invention, it is provided that the structural part containing the mouth or the opening roller housing with the fiber feeding duct, by means of fastening means causing an precise positioning, is fastened at the structural part receiving the shafts of the rollers. As a result, it is possible to in a simple way also subsequently exchange the parts that must be adjusted precisely to one another. If necessary, it is possible to exchange them for better suitable structural parts in the case of a changing-over to a different fiber material, without the requirement of special adjusting work.
In a further developement of the invention, it is provided that the part of the fiber feeding duct containing the mouth is worked into a narrow web-type structural component extending in the longitudinal direction of the wedge-shaped gap. As a result, the area of the rollers that must be made accessible for servicing is not significantly restricted. In order to nevertheless protect the rollers and also possibly prevent the entering of secondary air, in a further development of the invention, a covering for the rollers is provided which is arranged so that it can be moved away from the rollers, which together with the roller housing forms a chamber largely surrounding the rollers and which is equipped with a recess for the structural component containing the fiber feeding duct.
In a further development of the invention, it is provided that the fiber feeding duct can be connected to a compressed-air source in such a way that via the mouth of the fiber feeding duct a jet of compressed air can be blown into the wedge-shaped gap. As a result, it is ensured that also the area of the wedge-shaped gap is accessible, especially for cleaning. Also, after a yarn breakage, the wedge-shaped gap can be securely freed from fiber residues or similar material remaining in this area although the mouth of the fiber feeding duct is stationary in relation to the rollers. The removal of such fiber residues or similar materials can be carried out without difficulty by means of a jet of compressed air.
In a further developement of the invention, it is provided that the fiber feeding duct is contained in at least two structural parts that are arranged behind one another, of which the structural part that faces away from the mouth can be moved away in order to apply a compressed air supplying means to the other structural part. This ensures in a simple way that a sufficiently strong jet of compressed air can be aimed at the wedge-shaped gap.
In a further development of the invention, it is provided that the compressed air supplying means is a component of a movable servicing apparatus that can be applied to the arrangement. In an advantageous development, it is provided in this case that the servicing apparatus is equipped with means for moving away the structural component facing away from the mouth of the fiber feeding duct. These means, in a very simple way, may be realized by the fact that the servicing apparatus is equipped with a head piece that can be inserted between the two structural components. The head piece is advantageously equipped with two blow openings aimed into the two parts of the fiber feeding duct. The head piece may therefore, on the one hand, move the two structural components apart and is simultaneously used as the compressed air supplying means so that the expenditures for the driving element can be kept relatively low.
In a further development of the invention, it is provided that a suction pipe is aimed into the wedge-shaped gap which can be connected to a vacuum source. Via this suction pipe, it is possible to also remove the dirt that is detached in the wedge-shaped gap by the jet of compressed air. The cleaning process can thus be controlled better.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.